A major portion of training time involves advising the investigator on how best to use the various tools available at the BMIRR to address his/her particular question . This includes development of a clear idea about what is to be reconstructed in relationship to how it is to be analyzed (e.g. whether quantification, sophisticated surface rendering, or animation will be required). All users of Sterecon are trained in data input. This training takes about 15 min. With rare exceptions, the investigators do their own tracing, since only they are familiar enough with the specimen to make the needed judgements during tracing. Usually, a staff member does the visualization of the reconstructions, with the investigator present to explain what is to be demonstrated. A few investigators, who have an interest in computer techniques, are also trained to do the visualization. Training in visualization techniques takes about a week. We spend, on the average, 2 hour per w eek demon strating Sterecon to visitors and potential users. Finally, we aim many of our publications and meeting presentations at attracting new users. Sterecon also has a web homepage. It has been distributed to five laboratories so far.